Pluto is the smallest, coldest and most distant planet. We know little about her. Pluto may be just a small body in the solar system.

Pluto is the tenth and last planet in the solar system. Some astronomers believe that this is not a planet at all, but one of the small bodies of the solar system. There are a lot of such bodies, and they are divided into 3 main groups.

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What celestial bodies are called asteroids?

Asteroids are stone bodies of the planetary part of the solar system. Most of them are found in the Asteroid Belt between Mars and Jupiter. Further from the Sun is the Kuiper Belt with comet-like bodies, stretching from the orbit of Neptune to the outer borders of the solar system. On its outskirts is the spherical Oort Cloud, consisting of bodies of the third group - comets.

What is Pluto?

Pluto is a small ball of icy rocks that may have been captured by the sun's gravity and began to orbit around it in an orbit similar to that of a planet. It differs from the orbits of other planets by a slightly larger deviation from the circular one and, moreover, is tilted at an angle of 170 to the Earth's orbit. The distance from Pluto to the Sun varies from 4.45 billion km to 7.38 billion km. when Pluto approaches the Sun.

SourceA snapshot of Pluto's surface taken in 2015 at the time of the closest approach of the New Horizons probe from an altitude of 18 thousand km.

He turns out to be closer to him than Neptune. This happens 1 time during every 248-year period of Pluto's revolution around the Sun. Then it becomes the second planet in the distance from the Sun and remains so for 20 years, until it again moves away from it beyond the orbit of Neptune.

The video, which is part of ESA Hubblecast 27, introduces the artist's concept of Pluto's surface. Charon and the Sun in Pluto's sky. Pluto is so far from the Sun that it is very dark and cold.

Charon is a large satellite compared to the planet around which it orbits: its mass is about 25% of the mass of Pluto. This affects their movement. They both revolve around a common center of mass, so Pluto, like Charon, walks in circles.

It is always cold on Pluto, about -220 0 C. But when it comes closest to the Sun, part of the ice mantle turns into gas and forms the atmosphere.
From here, the Sun is seen 1000 times fainter than from the Earth.

Who discovered Pluto and when?

Pluto was discovered in 1930 by the American astronomer Clyde Tombaugh (1906 - 1997). Its satellite was discovered in 1978.

SourceIn the photo, who discovered Pluto - American astronomer Clyde Tombaugh

It is about half the size of Pluto and also consists of rock and ice. They circle each other like a double planet. At the same time, they rotate around their axis, always remaining turned to each other by the same side.

Asteroid belt in the solar system

Billions of asteroids revolve around the Sun. Over 90% of them make up the Asteroid Belt (or Main Belt) - a steering wheel-like ring between Mars and Jupiter. Sometimes they are called minor planets, because each of them is a stone body revolving around the Sun. This is material that could not coalesce into a planet 4.6 billion years ago, when the solar system was forming.

The first asteroid discovered by science

The first asteroid Ceres was discovered in 1801. It is also the largest of them, has a spherical shape and its diameter is about 932 km.

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Most asteroids are much smaller. About a billion - more than a kilometer in size, but many of them are only a few meters across. Asteroids are composed of stone, metal, or

How many asteroids is known to science

In total, over 10,000 individual asteroids have been discovered and their orbits have been cataloged. Each of them got its own name. All photographs of aseroids taken at close range were obtained by 2 spacecraft. The Gallileo probe in October 1991 photographed the asteroid Gaspra, and the NEAR probe (Near Earth Asteroid Rendezvous) transmitted images of the asteroids Matilda in 1997 and Eros in 1998. In February 2001, Gallileo landed on the surface of Eros.

Kuiper's belt and where is it located

The Kuiper Belt is named after the Dutch-born astronomer Jellal Kuiper (1905-1973).

It is a ring of comet-like bodies thought to be composed of ice, snow, rocks and dust. It is estimated that there are at least 70,000 such bodies with crossbars over 100 km. They are so far away that we cannot yet see only the close ones. The first such bodies were discovered in the last years of the 20th century.

The asteroid belt between Mars and Jupiter is made up of billions of asteroids. The largest of them, Ceres, has a diameter of 932 km and a surface dug by impact craters. Single asteroids outside the Belt move in their orbits in the inner part of the solar system . The Kuiper Belt, which includes tens of thousands of rock-ice bodies, lies beyond the orbit of Neptune.

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